Systems and methods for detecting chips in fluid of aircraft engine
There is described herein methods and systems for detecting electrically-conductive particles (chips) in fluid of an aircraft engine. The method comprises applying a plurality of excitation currents I i across a magnetic chip detector mounted to a fluid system of the aircraft engine and measuring a corresponding plurality of resistance values R i , where i is an integer that varies from 1 to N, and where N corresponds to a number of different excitation currents applied across the magnetic chip detector. The method further comprises determining a chip size indication Y from the plurality of resistance values R i , and detecting a chip in the fluid when the chip size indication Y exceeds a threshold Y thres .
1. A method for detecting electrically-conductive particles (chips) in fluid of an aircraft engine, the method comprising:
applying a plurality of excitation currents I i across a magnetic chip detector mounted to a fluid system of the aircraft engine and measuring a corresponding plurality of resistance values R i , where i is an integer that varies from 1 to N, and where N corresponds to a number of different excitation currents applied across the magnetic chip detector;
determining a chip size indication Y from the plurality of resistance values R i ; and
detecting a chip in the fluid when the chip size indication Y exceeds a threshold Y thres .
2. The method of claim 1 , wherein determining the chip size indication Y comprises summing the plurality of resistance values R i together to obtain the chip size indication Y.
3. The method of claim 2 , wherein summing the plurality of resistance values R i together comprises applying weighting factors X i to the plurality of resistance values R i prior to summing the resistance values R i .
4. The method of claim 3 , wherein the weighting factors X i are different for each one of the resistance values R i .
5. The method of claim 3 , wherein at least one of the weighting factors X i is null.
6. The method of claim 3 , further comprising receiving an input and selecting the weighting factors X i based on the input.
7. The method of claim 6 , wherein the input depends on at least one of a type of the aircraft engine, an oil type, an oil flow rate, a rotational speed of the aircraft engine, a capture rate of the magnetic chip detector, a target chip size for detection.
8. The method of claim 1 , wherein applying the plurality of excitation currents I i comprises varying a continuous excitation current successively across the plurality of excitation currents I i .
9. The method of claim 8 , wherein varying the continuous excitation current successively across the plurality of excitation currents I i comprises scanning a range of excitation currents at specific intervals.
10. The method of claim 9 , wherein applying the plurality of excitation currents I i comprises repeating said varying a continuous excitation current for a plurality of frequencies.
11. A detection system for an aircraft engine, for electrically-conductive particles (chips), the detection system comprising:
a processing unit; and
a non-transitory memory communicatively coupled to the processing unit and comprising computer-readable program instructions executable by the processing unit for:
causing a plurality of excitation currents I i to be applied across a magnetic chip detector mounted to a fluid system of the aircraft engine and receiving a corresponding plurality of resistance values R i , where i is an integer that varies from 1 to N, and where N corresponds to a number of different excitation currents applied across the magnetic chip detector;
determining a chip size indication Y from the plurality of resistance values R i ; and
detecting a chip in the fluid when the chip size indication Y exceeds a threshold Y thres .
12. The chip detection system of claim 11 , wherein determining the chip size indication Y comprises summing the plurality of resistance values R i together to obtain the chip size indication Y.
13. The chip detection system of claim 12 , wherein summing the plurality of resistance values R i together comprises applying weighting factors X i to the plurality of resistance values R i prior to summing the resistance values R i .
14. The chip detection system of claim 13 , wherein the weighting factors X i are different for each one of the resistance values R i .
15. The chip detection system of claim 13 , wherein at least one of the weighting factors X i is null.
16. The chip detection system of claim 13 , wherein the program instructions are further executable for receiving an input and selecting the weighting factors X i based on the input.
17. The chip detection system of claim 11 , wherein causing the plurality of excitation currents I i to be applied comprises varying a continuous excitation current successively across the plurality of excitation currents I i .
18. The chip detection system of claim 17 , wherein varying the continuous excitation current successively across the plurality of excitation currents I i comprises scanning a range of excitation currents at specific intervals.
19. The chip detection system of claim 18 , wherein causing the plurality of excitation currents I i to be applied comprises repeating said varying a continuous excitation current for a plurality of frequencies.
20. The chip detection system of claim 11 , further comprising the magnetic chip detector mounted to the fluid system of the aircraft engine and a resistance measurement circuit for applying the plurality of excitation currents I i across the magnetic chip detector and measuring the corresponding plurality of resistance values R i .